Liz Brown is hosting a gluten- and dairy-free Thanksgiving dinner for 32 people this year, but you wouldn't know what's missing by looking at the menu.

Liz has been retooling her recipes for the past four years, ever since her husband and three of her children were diagnosed with intolerance to gluten, a protein in wheat, oats, rye, barley and malt. Her husband, Chris, also has intolerance to casein, a protein in milk.

Despite the challenge of redefining the holiday meal, Liz won't break the 13-year streak of having the whole family over for the feast.

Maybe she's just happy to see her family eat with enthusiasm and painlessly, again.

For years meals weren't such joyful occasions in the Browns' Wheaton home.

"Mitchell (now 9) was 6 months and doing fine until we started oatmeal, and he became a bloated, crabby, irritable kid," Liz says of her firstborn. "Never once in the first five years of his life did he say 'I'm hungry.'"

He suffered stomach pain all the time and headaches, he was lethargic and food did not appeal to him. The doctor recommended antacids at age 5, to no avail.

"No one could tell us what was wrong," Liz says.

In the meantime, four years ago Chris went on a weekend trip with friends and came home with mysterious digestive issues that eventually caused a 40-pound weight loss and unexplained pain.

Like an episode of Fox Network's popular medical drama "House," the Browns puzzled over possible diagnoses. They became more frustrated as infant daughter, Lily, now 5, and son Nolan, now 3, both developed problems as they were introduced to solid foods. Liz was determined to figure it out.

"I was up until 2 a.m. on the computer every night for nine months," Liz says. "One night at midnight I stumbled across an article about gluten intolerance and almost fell out of my chair. I thought, 'This is Mitch.'"

The next day Liz dashed out to a Whole Foods market and bought "everything I could that was gluten free." Within 36 hours "Mitch became a different person," no longer irritable and picky about food.

Within two months he went from eating five foods to devouring anything put in front of him.

In the meantime, the rest of the family improved on the same diet.

With loaves of bread at more than $6, Liz knew she had to control costs for her family of six. She began researching gluten- and casein-free recipes, combing the Internet and buying cookbooks. She learned how to bake all the family's muffins, sandwich bread, hamburger and hot dog buns and pizza crust using a blend of rice flour, potato starch and tapioca flour in place of all-purpose wheat flour.

The first Thanksgiving without gluten and dairy "was not as good as the next," she says, but with practice she perfected her techniques.

This year's menu will start with turkey sausage and honey mustard dip, chips with soy sour cream and onion and perhaps bruschetta on gluten-free bread.